CN100552865C - ion implanter - Google Patents

Abstract

An ion implantation apparatus, comprising: an ion source that generates a sheet-like ion beam (20) having desired ion species and wider than the width of a short side of a substrate (82); a mass separation magnet (36) that makes The ion beam (20) bends in a direction perpendicular to its sheet surface (20s), and screens and derives the desired ion species; the separation gap (72), which cooperates with the mass separation magnet (36), screens the desired ion species and make it pass through; the substrate driving device (86), which is substantially perpendicular to the sheet surface (20s) of the ion beam (20) in the irradiation area of the ion beam (20) passing through the separation gap (72) The substrate (82) is repeatedly driven.

Description

ion implanter

technical field

The present invention relates to, for example, an ion implantation device for irradiating an ion beam on a substrate such as a semiconductor substrate or a substrate for a flat panel display (in other words, a processed object or an object to be processed, the same applies hereinafter), and more specifically relates to An ion implantation apparatus that can well cope with an increase in the size of a substrate (in other words, increase in area; the same applies hereinafter). In addition, a device called ion doping is also included in the ion implantation device referred to here.

Background technique

Japanese Patent Application Publication No. 2000-505234 (page 14, line 14 to page 15, line 15, FIG. 1 ) describes an example of an ion implanter capable of irradiating a substrate with a wide and parallelized ion beam. This ion implanter has a structure in which a fan-shaped ion beam diverging in one direction is extracted from a small ion source, and the ion beam is bent in a plane parallel to the fan plane by a mass separation magnet serving as a beam parallelizing magnet, thereby screening ( Mass separation) of desired ion species is parallelized to form a wide and parallelized ion beam, and the ion beam is irradiated to the substrate.

In the ion implanter, the mass resolving power of the mass separation magnet is high in the outer peripheral portion of the ion beam deflection region and low in the inner peripheral portion. This is because in order to bend and parallelize the ion beam, the deflection angle becomes larger toward the outer periphery, and the mass resolving power becomes higher. However, since the higher the mass resolving power, the stricter the screening of ion species, the less the amount of ion species obtained, the beam current density of the ion beam derived from the mass separation magnet forms a low position passing through the outer periphery, and a lower position passing through the inner periphery. The position of the part is high such an uneven distribution. That is, the uniformity of the beam current density distribution in the ion beam width direction deteriorates.

In the ion implantation apparatus described in the above-mentioned Japanese Patent Application Publication No. 2000-505234 (line 14 on page 14 to line 15 on page 15, FIG. The polar ion lens uses the local deflection of ions to correct the inhomogeneity of the beam current density distribution caused by the above reasons (for example, bending the ion beam to the side of the low current density area to increase the current density in this area), but the above reasons cause The inhomogeneity of beam current density distribution is very large, and it is limited to correct it by using multipole ion lens.

In addition, when the ion beam is largely deflected by the multipolar ion lens to correct the non-uniformity of the beam current density distribution, this deflection causes another problem of deterioration of the parallelism in the width direction of the ion beam.

Such a problem becomes more serious when the width of the ion beam guided from the mass separation magnet is increased in accordance with the enlargement of the substrate (for example, a substrate having a shorter side width of about 600 mm or more).

In addition, in the above-mentioned prior art that utilizes the divergence of the ion beam extracted from the ion source to widen the width of the ion beam, since the beam current density becomes lower as the width of the ion beam becomes wider, when corresponding to an increase in the size of the substrate, The processing speed per substrate is reduced.

Contents of the invention

Therefore, the main object of the present invention is to provide an ion implantation apparatus which can suppress the decrease in the uniformity of the beam current density distribution in the width direction of the ion beam, the deterioration in the parallelism, and the decrease in the substrate processing speed, and at the same time, it can cope with the large size of the substrate. change.

The ion implantation apparatus of the present invention transports a sheet-shaped ion beam generated by an ion source that is wider than the width of the short side of the substrate to the substrate while maintaining the width relationship, and irradiates the substrate, and is characterized in that it includes: source, which contains the ion species desired to be implanted into the substrate and generates a sheet-shaped ion beam having said width relationship, for generating plasma as a source of the sheet-shaped ion beam, having a plurality of arrays arranged in the width direction of the sheet-shaped ion beam a filament; more than one filament power supply, which can independently control the filament current flowing into each filament of the ion source; a mass separation magnet, which receives the sheet-shaped ion beam generated by the ion source, has a ratio greater than that of the ion source. The spaced magnetic poles with a large width of the ion beam bend the ion beam in a direction perpendicular to its sheet surface to screen and extract the desired ion species; the separation gap receives the sheet-shaped ions derived from the mass separation magnet The beam, cooperating with the mass separation magnet, screens the desired ion species to pass through; the substrate driving device, which has a support frame for holding the substrate, is in the irradiation area of the sheet-shaped ion beam passing through the separation gap reciprocatingly driving the substrate on the support frame in a direction intersecting the sheet surface of the ion beam; an electrostatic lens or a magnetic lens, between the ion source and the mass separation magnet or between the mass separation magnet and the mass separation magnet Between the separation gaps, the beam current density distribution in the width direction of the sheet-shaped ion beam is made uniform.

According to this ion implantation apparatus, a sheet-shaped ion beam generated by an ion source that is wider than the width of the short side of the substrate can be transported while maintaining the width relationship, and the desired ion species can be screened through the mass separation magnet and the separation gap (i.e. performing mass separation), irradiating the substrate on the support frame, and performing ion implantation. In addition, ion implantation can be performed on the entire surface of the substrate by cooperation of the sheet-shaped ion beam having the above width relationship and the reciprocating drive of the substrate by the substrate driving device.

An electrostatic lens or a magnetic lens for uniformizing the current density distribution in the width direction of the sheet-shaped ion beam may be provided between the ion source and the separation gap.

A first auxiliary magnetic pole and a second auxiliary magnetic pole for parallelizing the magnetic field between the main magnetic poles may be provided on the outer peripheral side and the inner peripheral side of the main magnetic poles of the mass separation magnet. The distance between at least one of the two secondary magnetic poles may be made variable in advance.

A movable magnetic pole may be provided on at least one side of the inlet and outlet of the magnetic pole (main magnetic pole if there is an auxiliary magnetic pole) of the mass separation magnet.

A scanning electrode for repeatedly scanning the entire sheet-like ion beam in a direction perpendicular to the sheet-like surface may be provided on the downstream side of the separation slit.

A beam profile monitor for receiving the sheet-shaped electron beam and measuring the beam current density distribution in the width direction may be provided upstream or downstream of the substrate on the support frame.

A control device may also be provided, which controls the filament power supply, the electrostatic lens DC power supply for the electrostatic lens, the magnetic lens DC power supply for the magnetic lens, the auxiliary The auxiliary magnetic pole drive unit for the magnetic pole or the movable magnetic pole drive unit for the movable magnetic pole controls uniform beam current density distribution in the width direction of the sheet-shaped ion beam incident on the substrate.

According to the first aspect of the present invention, since the sheet-shaped ion beam generated by the ion source is wider than the short side width of the substrate, it is transported to the substrate in a state maintaining the relationship of the width, and, in the mass separation magnet, the The ion beam is not only bent in the direction of its width, but also in the direction perpendicular to the sheet surface to perform mass separation, so the sheet-shaped ion beam generated by the ion source can be kept uniform and parallel to the beam current density in the width direction. Mass separation is carried out under the premise of deteriorating properties, and it is incident on the substrate. In other words, poor mass resolving power due to positional differences of bent ion beams, uniformity of beam current density and deterioration of parallelism of ion beams due to correction thereof do not occur as in the above-mentioned prior art. In addition, it is possible to easily respond to an increase in the size of the substrate by generating and transporting a sheet-like ion beam having a width corresponding to the width of the short side of the substrate from the ion source. Therefore, it is possible to suppress the decrease in the uniformity of the beam current density distribution in the width direction of the ion beam and the deterioration in the parallelism, and cope with an increase in the size of the substrate.

In addition, since the ion source has the above-mentioned plurality of filaments, and the filament currents flowing into the respective filaments can be independently controlled, for example, it is easy to generate a sheet-like ion beam with a uniform beam current density distribution in the width direction.

Moreover, since the sheet-shaped ion beam having the width relationship is generated from the ion source and is transported to the substrate while maintaining the width relationship, it is not possible to generate a beam-like ion beam using the ion beam as described in the prior art. The divergence widens the width and reduces the beam current density. That is, the increase in the size of the substrate can be easily dealt with by generating and transporting a sheet-shaped ion beam whose width corresponds to the width of the short side of the substrate, thereby preventing a reduction in the beam current density, and thus reducing the cost per substrate. The processing speed can cope with the increase in the size of the substrate.

According to the second aspect based on the first aspect of the present invention, the following higher effect can be obtained. The beam current density distribution in the width direction of the sheet ion beam can be adjusted through the electrostatic lens, and its uniformity can be further improved.

According to the third aspect based on the second aspect of the present invention, the following higher effect is obtained. The electrostatic lens can control the beam emission density as described above, whereby the microscopic (subtle) beam current density distribution in the width direction of the ion beam can be adjusted. The) non-uniformity is flattened, so the uniformity of the beam current density distribution in the width direction of the sheet ion beam can be further improved.

According to the fourth aspect based on the first aspect of the present invention, the following higher effect is obtained, the beam current density distribution in the width direction of the sheet ion beam can be adjusted by using the magnetic lens, and its uniformity can be further improved.

According to the fifth aspect based on the fourth aspect of the present invention, the following higher effect is obtained, the electrostatic lens can control the beam emission density as described above, thereby, the microscopic (subtle) beam current density distribution in the width direction of the ion beam can be adjusted. The) non-uniformity is flattened, so the uniformity of the beam current density distribution in the width direction of the sheet ion beam can be further improved.

According to the sixth aspect based on the first aspect of the present invention, the following higher effect is obtained, since the magnetic field between the main magnetic poles can be parallelized by the magnetic field between the first sub-magnetic poles and the magnetic field between the second sub-magnetic poles. When the sheet ion beam is bent, the generation of Lorentz force along the direction of the ion beam sheet surface can be suppressed, and the generation of convergence or divergence in the width direction of the ion beam can be suppressed. As a result, the parallelism in the width direction of the sheet-shaped ion beam can be further improved, and the uniformity of the beam current density distribution in the width direction of the ion beam can be further improved.

According to the seventh aspect based on the sixth aspect of the present invention, a higher effect can be obtained, and adjustment to further parallelize the magnetic field between the main magnetic poles can be performed.

According to the eighth aspect of the present invention based on the seventh aspect, a higher effect is obtained in that adjustment to further parallelize the magnetic field between the main magnetic poles is easily performed by using the sub-magnetic pole drive device.

According to the ninth aspect based on the first aspect of the present invention and the tenth aspect based on the sixth aspect, the following higher effect is obtained, because the ion beam passing through the vicinity of the movable electrode can be concentrated or diverged by adjusting the angle and utilizing the edge focusing effect , so the divergence of the ion beam caused by the Coulomb repulsion acting on the width direction of the ion beam can be compensated, and the parallelism of the ion beam can be further improved, thereby further improving the uniformity of the beam current density distribution in the width direction of the ion beam.

According to the eleventh aspect based on the ninth aspect of the present invention, a higher effect is obtained in that the angle of the movable electrode can be easily adjusted by using the movable magnetic pole drive means.

According to the twelfth aspect based on the first aspect of the present invention, there is obtained a higher effect that the thickness of the ion beam can be increased by making the thickness of the separation slit (which is also the width in the direction in which the substrate is repeatedly driven) very small. When the thickness of the ion beam is very small, although the unevenness of the implantation amount may be caused by the repeated driving speed of the substrate or the fluctuation of the ion beam current value, the unevenness can be alleviated by increasing the thickness of the ion beam.

According to the thirteenth aspect based on the first aspect of the present invention, a higher effect is obtained. Since the measurement information based on the beam profile monitor can be used, it is possible to easily improve the beam current density distribution in the width direction of the sheet-shaped ion beam. Adjustment for uniformity or parallelism.

According to the fourteenth aspect based on the first aspect of the present invention, the following higher effect is obtained. By using the beam profile monitor and the control device to feedback control the filament electrode current of the ion source, the ion beam incident on the substrate can be improved by automatic control. The uniformity of the beam current density distribution in the width direction of the ion beam.

According to the fifteenth aspect based on the second aspect of the present invention, the following higher effect is obtained, by using the beam profile monitor and the control device to feedback control the electrostatic lens, the width of the sheet-shaped ion beam incident on the substrate can be increased by automatic control The uniformity of the beam current density distribution in the direction.

According to the sixteenth aspect based on the fourteenth aspect of the present invention, the following higher effect is obtained. By using the beam profile monitor and the control device to feedback control the magnetic lens, the sheet-shaped ion beam incident on the substrate can be improved by automatic control. Uniformity of beam current density distribution in the width direction.

According to the seventeenth aspect based on the eighth aspect of the present invention, a further higher effect is obtained. By using the beam profile monitor and the control device to feedback control the interval of the sub-magnetic poles of the mass separation magnet, the incidence on the substrate can be increased by automatic control. The parallelism of the sheet ion beam width direction and the uniformity of beam current density distribution.

According to the eighteenth aspect based on the eleventh aspect of the present invention, a higher effect is obtained. By using the beam profile monitor and the control device to feedback control the angle of the movable magnetic pole of the mass separation magnet, the angle of the movable magnetic pole of the mass separation magnet can be increased by automatic control. The parallelism of the sheet ion beam width direction on the bottom and the uniformity of beam current density distribution.

Description of drawings

Fig. 1 is a cross-sectional view showing a part of an embodiment of the ion implantation apparatus of the present invention, and the part of the line A1-A1 is joined to Fig. 2;

Fig. 2 is a cross-sectional view showing the remaining part of an embodiment of the ion implantation apparatus of the present invention, and the part of the line A1-A1 is connected with Fig. 1;

Fig. 3 is a longitudinal sectional view showing a part of the ion implantation apparatus shown in Fig. 1 and Fig. 2, and the part of the line A2-A2 is connected to Fig. 4;

Fig. 4 is a longitudinal sectional view showing the remaining part of the ion implantation apparatus shown in Fig. 1 and Fig. 2, and the part of the line A2-A2 is connected with Fig. 3;

Fig. 5 is a perspective view of ion beam simplified and partially represented;

Fig. 6 is a front view showing an example of the relationship between the ion beam and the substrate;

7 is a diagram showing an example of an electrostatic lens and its power supply;

Fig. 8 is a plan view showing another example of a mass separation magnet by enlarging its magnetic pole part, which is equivalent to the magnetic pole part in Fig. 1 and Fig. 2;

Fig. 9 is a longitudinal sectional view showing another example of an enlarged mass separation magnet, roughly corresponding to the K-K section of Fig. 8;

Fig. 10 is a diagram showing another example of an electrostatic lens and its power supply;

Fig. 11 is a diagram showing an example of a magnetic lens and its power supply;

Fig. 12 is a diagram showing a more specific example of the connection between each excitation coil and each power supply in Fig. 11;

Fig. 13 is a diagram showing another example of a magnetic lens and its power supply.

Detailed ways

FIG. 1 is a cross-sectional view showing a part of the ion implantation apparatus of the present invention, and the line A1-A1 is connected to FIG. 2 . Fig. 2 is a cross-sectional view showing the remaining part of the ion implantation apparatus of the present invention, and the part on the line A1-A1 is connected to Fig. 1 . 3 is a longitudinal sectional view showing a part of the ion implantation apparatus shown in FIGS. 1 and 2 , and a portion on line A2-A2 is connected to FIG. 4 . FIG. 4 is a vertical cross-sectional view showing the rest of the ion implantation apparatus shown in FIGS. 1 and 2 , and the portion on the line A2-A2 is connected to FIG. 3 .

In principle, this ion implantation apparatus uses, for example, a rectangular substrate 82 as shown in FIG. 6 as an object to be processed. The width of the short side 82a of the substrate 82 is referred to as the short side width WS. However, when the substrate 82 is square or circular, the length or diameter of one side and the width WS of the short side may be treated in the same manner. Thus, a square or circular substrate 82 can also be processed as a target object. The substrate 82 is, for example, a semiconductor substrate, a substrate for a flat panel display (for example, a glass substrate), or the like.

This ion implantation apparatus has a structure in which the sheet-like ion beam 20 generated by the ion source 2 and having a width WB (see FIGS. > WS) state is transported to the substrate 82 held on the support frame 84 in the processing chamber container 80 through the electrostatic lens 24, the mass separation magnet 36, the separation gap 72, etc., and the substrate 82 is irradiated, and the substrate 82 is irradiated. The bottom 82 is implanted with ions.

The path (beam line) of the ion beam 20 from the ion source 2 to the processing chamber container 80 is surrounded by a vacuum container 34 . At least the inside of the mass separation magnet 36 and the front and rear parts of the vacuum container 34 are made of a non-magnetic material. The insides of the ion source 2, the vacuum container 34, and the processing chamber container 80 are evacuated to a vacuum by a vacuum exhaust device (not shown) during operation of the ion implantation apparatus. The vacuum container 34 and the processing chamber container 80 are electrically grounded.

Ion source 2 generates sheet ion beam 20 containing ion species desired to be implanted into substrate 82 and having the width relationship described. "Desired" may also be referred to as prescribed or specified (the same applies hereinafter). The desired ion species can be determined by ion mass and valence.

5 schematically shows an example of a sheet-shaped ion beam 20 . As shown in the figure, the cross-sectional shape of the sheet-shaped ion beam 20 perpendicular to its advancing direction is a substantially rectangular shape elongated in the Y direction (for example, the vertical direction, the same below). This is probably because the actual cross-sectional shape of the ion beam 20 is not a perfect rectangular shape as shown in the figure, but the outer peripheral boundary is slightly blurred and cannot be clearly defined as drawn by the lines.

In this specification, the dimension along the direction of the long axis 20a of the rectangular section is called width WB, the dimension along the direction of short axis 20b is called thickness TB, and the main surface (including the surface of width WB) of the sheet ion beam is called The central axis in the advancing direction of the ion beam 20 is called the central axis 20c. Therefore, the direction of the width WB of the ion beam 20 is synonymous with the direction of the major axis 20a, and the direction of the thickness TB is synonymous with the direction of the minor axis 20b. In addition, in this embodiment, the direction of the width WB of the ion beam 20 is synonymous with the Y direction.

The sheet ion beam 20 is an ion beam whose thickness TB is sufficiently smaller than its width WB (for example, approximately 1/10 to 1/100), and in other words may be called a ribbon ion beam.

The ion source 2 is called a barrel-type ion source in this example, and has a rectangular box-shaped plasma generation container 4 that is long in the width WB direction of the ion beam 20 and has one side open. Into the plasma generation container 4, a source gas containing a material that is a source of the desired ion species is introduced.

A plurality of hot cathode filaments 6 are arranged at equal intervals in the plasma generation container 4 along the width WB direction of the ion beam 20 . The number of filaments 6 is not limited to three as shown in FIG. 3 , and may be determined corresponding to the width WB of the ion beam 20 . For example, when the width WB is about 800 mm, the number of filaments 6 may be about six.

A filament power supply capable of controlling the filament currents flowing into the respective filaments 6 independently of each other is provided. As an example thereof, in this example, as shown in FIG. 3 , an independent filament power source 8 is provided for each filament 6 . That is, the filament power source 8 with variable voltage is set according to the number of filaments 6 . However, instead of providing such an arrangement, a plurality of power supplies may be integrated into one, and one filament power supply may be used, and the filament current flowing into each filament 6 may be controlled independently of each other.

As described above, since the ion source 2 has such a plurality of filaments 6, and the filament currents flowing into the respective ion beams 6 can be controlled independently of each other, the density distribution of the plasma 10 in the width WB direction of the ion beam 20 The uniformity of the beam current density in the width WB direction is good, and the sheet-like ion beam 20 with good uniformity in the beam current density distribution in the width WB direction is easily produced.

That is, an arc discharge can be generated between each of the filaments 6 and the plasma generation container 4 to ionize the raw material gas, and the plasma 10 in which the width WB of the ion beam 20 is long distributed in the plasma generation container 4 can be generated uniformly. .

An extraction electrode system 12 for extracting the sheet-shaped ion beam 20 from the plasma 10 by the action of an electric field and accelerating it to a desired energy is provided near the opening of the plasma generation container 4 . The extraction electrode system 12 has three electrodes 14-16 in this example. But not limited to three. Each of the electrodes 14 to 16 may have a slit longer than the width WB of the ion beam 20 as an ion extraction hole, or may have a plurality of (many) small holes arranged along the width WB or more of the ion beam 20 . Figure 3 shows the case with gaps, but the latter is better. This is because the latter can make the beam current density distribution in the width WB direction of the ion beam 20 more uniform.

With the above structure, a sheet-like ion beam 20 having a uniform beam current density distribution in the width WB direction is extracted from the ion source 2, more specifically, from the plasma 10 generated in the ion generating container 4, which contains The ion species that are desired to be implanted into the substrate 82 have the above-mentioned width relationship.

On the downstream side of the ion source 2 (in other words, the advancing direction side of the ion beam 20, the same below), a mass separation magnet 36 is provided, which receives the sheet-shaped ion beam 20 generated by the ion source 2, and has a ratio greater than that of the ion beam 20. The magnetic pole (specifically, the main magnetic pole 38) of the interval L1 with a large width WB (that is, L1>WB) bends the ion beam 20 in a direction perpendicular to the sheet surface 20s to extract the desired ion species ( That is, mass separation is performed), and the sheet-shaped ion beam 20 is extracted. As described above, since L1>WB, the ion beam 20 can pass through the mass separation magnet 36 as it is while maintaining its parallelism. The mass separation magnet 36 will be described in detail below.

In the mass separation magnet 36, the ions constituting the ion beam 20 are given their own orbital radius corresponding to their mass, and on the downstream side of the mass separation magnet 36, desired ion species are focused along the thickness TB direction of the ion beam 20. A separation gap 72 is provided near the position of the mass separation magnet 36 to receive the sheet-shaped ion beam 20 derived from the mass separation magnet 36, cooperate with the mass separation magnet 36 to screen the desired ion species and pass it through. As shown in FIG. 4 , the length in the direction of the width WB of the ion beam 20 of the separation gap 72 is longer than the width WB.

In this example, as shown in FIG. 2 , the separation slit 72 can move around the center 70 as indicated by arrow C, whereby the opening (slit width) of the separation slit 72 can be changed mechanically. Thereby, the resolving power of mass separation can be changed. For example, the narrower the slit width, the higher the resolving power, but the lower the resulting beam current density. In phosphine ions (PHx ⁺ ) having a wide range of molecular weights corresponding to the number of bonds of hydrogen, the mass resolving power (M/ΔM, where M is the mass and ΔM is its difference) is about 5 is appropriate, but the opposite ion source 2 It is preferable that the boron ion (B ⁺ ) of BF3 used as the raw material gas supplied is about 8.

A substrate drive 86 is arranged in the process chamber container 80 downstream of the separation gap 72 . The substrate driving device 86 has a support frame 84 for holding the substrate 82, and the substrate 82 on the support frame 84 is moved with the ion beam 20 at a certain speed in the irradiation area of the ion beam 20 passing through the separation gap 72. The sheet-like surfaces 20s are reciprocally driven in the direction crossing, as shown by arrow D (refer to FIG. 6 ). In this example, the reciprocating direction of the substrate 82 on the support frame 84 is a direction substantially perpendicular to the sheet surface 20s of the ion beam 20 (that is, a direction intersecting at or around 90 degrees, the same applies hereinafter). More specifically, referring to FIG. 2 , it is a direction substantially perpendicular to the central axis 20 c of the ion beam 20 and the surface of the substrate 82 . However, it may reciprocate in directions intersecting at an angle slightly smaller than 90 degrees (for example, about 80 degrees) or slightly larger than 90 degrees (for example, about 100 degrees).

In this example, as indicated by an arrow D, the substrate driving device 86 itself reciprocates along an unillustrated track. In this way, the entire surface of the substrate 82 can be irradiated with the ion beam 20 of a desired ion species to perform ion implantation. This ion implantation can be used in the step of forming a plurality of thin film transistors (TFTs) on the surface of the substrate 82 for a flat panel display.

In the processing chamber container 80, for example, two substrate driving devices 86 may be arranged in front and behind in the beam advancing direction, and the two substrate driving devices 86 are alternately used to alternately operate the substrates 82 respectively held on the supporting racks 84 thereof. Ion Implantation. Thereby, productivity is improved.

According to this ion implantation apparatus, since the sheet-shaped ion beam 20 generated by the ion source 2 and having a width WB wider than the width WS of the short side of the substrate 82 is transported to the substrate 82 while maintaining the width relationship (that is, WB>WS). , and, use mass separation magnet 36 to make ion beam 20 not to its width WB direction but to the direction perpendicular to sheet-like surface 20s, carry out mass separation, so the sheet-like ion beam 20 that can be produced by ion source 2 is not In a state in which the uniformity and parallelism of the beam current density in the width WB direction are deteriorated, mass separation is performed and the beam is incident on the substrate 82 . That is, poor mass resolving power due to differences in the position where the ion beam is bent, deterioration of the uniformity of the beam current density distribution associated with it, and parallelization of the ion beam due to correction thereof will not occur as in the above-mentioned prior art. Sexual deterioration. Furthermore, the increase in size of the substrate 82 can be easily dealt with by generating and transporting the sheet-like ion beam 20 having a width WB corresponding to the width WS of the short side of the substrate 82 from the ion source 2 . Therefore, reduction in the uniformity of the beam current density distribution and deterioration in parallelism in the width WB direction of the ion beam 20 can be suppressed, and an increase in the size of the substrate 82 can be accommodated. For example, a substrate 82 having a short side width WS of 800 mm, 1000 mm or more can be handled.

In addition, since the ion source 2 has a plurality of filaments 6 as described above, and the filament current flowing into each filament 6 can be independently controlled, the density distribution of the plasma 10 in the width WB direction of the ion beam 20 can be improved. The uniformity of the beam current density in the width WB direction can be easily produced in the sheet-shaped ion beam 20 with good uniformity of the beam current density distribution.

Moreover, since the ion source 2 generates the sheet-shaped ion beam 20 having the relationship of the width described above, and the ion beam 20 is transported to the substrate 82 while maintaining the relationship of the width, the above-mentioned prior art does not occur. In this method, the divergence of the ion beam is used to increase the beam current density due to the increase in width, that is, for the enlargement of the substrate 82, it is easy to generate and transport the sheet-like ion beam 20 having a width WB corresponding to the width WS of the short side of the substrate 82. Therefore, it is possible to cope with an increase in the size of the substrate 82 without reducing the processing speed per substrate, thereby preventing a reduction in the beam current density.

The ion implantation apparatus of this embodiment will be further described below. Preferably, a gate valve 22 with a rectangular opening is provided in advance between the ion source 2 and the electrostatic lens 24 (or magnetic lens 100) described later as in this embodiment. In this way, since the maintenance of the filaments of the ion source 2 can be performed while maintaining a vacuum inside the vacuum container 34 or the processing chamber container 80 on the downstream side of the gate valve 22, the maintenance time of the ion implantation apparatus after the maintenance can be greatly shortened. Debug time again.

Preferably, on the upstream side of the mass separation magnet 36, that is, between the ion source 2 (the gate valve 22 is installed) and the mass separation magnet 36, the static tortoise lens 24 that uniformizes the beam current density distribution in the width WB direction of the ion beam 20 is set. .

Referring to FIG. 7, the electrostatic lens 24 has a plurality (for example, 10 pairs) of electrode pairs, which are pairs (electrode pairs) of opposite electrodes 26 across the sheet-like surface 20s of the sheet-like ion beam 20, which are along the sheet. The shape surfaces 20s are arranged side by side in multiple stages in a direction perpendicular to the beam advancing direction (in other words, the width WB direction or the Y direction, the same applies below). The vicinity of the front end of each electrode 26 is formed in a semi-cylindrical or semi-cylindrical shape. As shown in FIG. 7 , two electrodes 26 that face each other and constitute a pair are electrically connected in parallel. Also, it is possible to see in FIG. 7 that the lines for this parallel connection cut across the ion beam 20 , but this is due to simplification of the illustration, in reality the lines do not cut across the ion beam 20 .

Between the electrode pairs of each stage and the reference potential part (for example, the ground potential part), as an example of an electrostatic lens DC power supply that applies mutually independent DC voltages, as shown in FIG. The stage electrodes are independent of a variable voltage electrostatic lens DC power supply 32 . That is, the number of electrostatic lens DC power supplies 32 is provided for the number of electrode pairs. However, it is also possible not to set up in this way, but to combine multiple power supplies into one, and one electrostatic lens DC power supply can be used to independently control the DC voltage applied to each electrode pair.

The DC voltage applied to the electrode pairs of each stage is preferably a negative voltage compared to a positive voltage. When a negative voltage is applied, electrons present in the plasma around the ion beam 20 together with the ion beam 20 are prevented from being introduced into the electrode 26 . While the divergence of the ion beam 20 due to space charge effects increases when the electrons are introduced, this can be prevented.

By adjusting the DC voltages applied to the electrode pairs at various levels, an electric field E can be generated in the direction of the width WB of the ion beam 20 (the electric field E in FIG. The ions are bent along the width WB direction.

Therefore, the electrostatic lens 24 can bend the ions in any region of the ion beam 20 along the width WB direction, adjust the beam current density in the width WB direction of the ion beam 20, and further improve its uniformity.

In addition, the multi-stage parallel electrode pairs do not necessarily need to be arranged at equal intervals in the width direction of the ion beam 20, in order to suppress the interaction between ions that strongly act on the two ends of the sheet-shaped ion beam 20 near the width WB direction. In order to avoid beam divergence due to strong Coulomb repulsion, etc., the electrode pairs may be arranged densely near both ends in the width WB direction of the ion beam 20 .

As shown in FIGS. 1 and 3 , shield plates 28 and 30 may be provided on the upstream and downstream sides of the electrodes 26 constituting the electrostatic lens 24 . The two shielding plates 28, 30 are connected to the vacuum container 34 and electrically grounded. When the shielding plates 28 and 30 are provided, leakage of the electric field from the electrode 26 to the upstream side and the downstream side of the electrostatic lens 24 can be prevented. As a result, an undesired electric field can be prevented from acting on the ion beam 20 near the upstream side and the downstream side of the electrostatic lens 24 .

As in the example shown in Figure 10, an electrostatic lens vibration power supply 96 can also be set instead of the electrostatic lens DC power supply 32, and the electrostatic lens vibration power supply 96 applies a vibration voltage between the odd and even electrode pairs of the electrostatic lens 24 to make the electrostatic lens The electric field intensity of 24 vibrates periodically to control the beam emission density of the sheet ion beam 20 in the WB direction. For example, the electrostatic lens vibration power supply 96 is an AC power supply, and the vibration voltage is an AC voltage, but it is not limited to an AC such that the average value of one cycle is zero.

When the electrostatic lens vibration power supply 96 is provided, the beam emission density can be controlled as described above in the electrostatic lens 24, thus, the microcosmic (slight) inhomogeneity of the beam current density distribution in the width WB direction of the ion beam 20 can be reduced. Therefore, the uniformity of the beam current density distribution in the width WB direction of the sheet-shaped ion beam 20 can be further improved.

The electrostatic lens vibration power supply 96 can also be provided together with the electrostatic lens DC power supply 32 . That is, both power sources 32 and 96 may be used in combination. At this time, as shown by the dotted line in FIG. 10 , a capacitor 98 is inserted in series in the circuit connecting the odd-numbered electrode pairs, as long as it can prevent the odd-numbered electrode pairs from being connected in parallel. The same can be done between even-numbered electrode pairs. In this way, the DC voltage from the electrostatic lens DC power supply 32 and the vibration voltage from the electrostatic lens vibration power supply 96 can be superimposedly applied to each electrode pair.

As mentioned above, when the two power supplies 32 and 96 are used together, the following two aspects can be used together, that is, the microscopic inhomogeneity of the beam current density distribution in the width WB direction of the ion beam 20 is flattened by using the electrostatic lens vibration power supply 96 , and use the electrostatic lens DC power supply 32 to flatten the greater inhomogeneity, so the uniformity of the beam current density distribution in the width WB direction of the ion beam 20 can be further improved.

In addition, the homogenization of the beam current density distribution achieved by performing the filament current control of the ion source 2 is macroscopic homogenization (that is, the uniformity of greater variation) compared with the homogenization realized by the electrostatic lens 24. By using the two aspects together, the composite effect of macroscopic homogenization and microscopic homogenization can be used to make the beam current density distribution extremely uniform.

Instead of the electrostatic lens 24, a magnetic lens such as that shown in FIG. 11 may also be provided. This magnetic lens 100 has a plurality of (for example, 10 pairs) magnetic pole pairs arranged in parallel in multiple stages at right angles to the advancing direction of the beam along the sheet surface 20s, and a plurality of excitation coils 104 for respectively exciting each magnetic pole pair, wherein, The plurality of magnetic pole pairs are pairs of magnetic poles 102 (magnetic pole pairs) facing each other across the sheet-like surface 20 s of the sheet-like ion beam 20 .

The back of each magnetic pole 102 is magnetically connected by a yoke 106 . The path of the ion beam 20 at the tip of each magnetic pole 102 is surrounded by a vacuum container 108 made of a non-magnetic material.

A plurality of magnetic lens DC power supplies 110 are provided to supply DC currents to the excitation coils 104 for the respective magnetic pole pairs. That is, the magnetic lens DC power supply 110 is provided according to the number of magnetic pole pairs. At least the magnitude of the output current of each power supply 110 is variable. In addition, each power supply 110 is preferably a bipolar power supply, which can reverse the direction of the output current.

Fig. 11 simplifies wiring, but as shown in Fig. 12, the excitation coils 104 wound on the paired two magnetic poles 102 are connected in series with each other and connected with the magnetic lens DC power supply 110 to generate magnetic fields B in the same direction. The same applies when connecting to the magnetic lens vibration power supply 112 described later.

The direct current flowing into the excitation coil 104 of each level of magnetic pole pairs can be adjusted, the magnetic field B generated by each level of magnetic pole pairs can be adjusted, and the Lorentz force F acting on the width WB direction of the ion beam 20 can be adjusted (magnetic field B and B in FIG. 11 ). The Lorentz force F is an example thereof), and bends the ions in the ion beam 20 in the width WB direction.

Therefore, the magnetic lens 100 can bend the ions in any region of the ion beam 20 to the width WB direction, adjust the beam current density distribution in the width WB direction of the ion beam 20, and further improve its uniformity.

The magnetic pole pairs arranged in multiple stages do not necessarily have to be arranged at equal intervals in the width WB direction of the ion beam 20 , which is the same as the case of the electrode pairs of the electrostatic lens 24 .

As in the example shown in FIG. 13 , instead of the magnetic lens DC power supply 110, a plurality of magnetic lens vibration power supplies 112 may be provided. The magnetic field strength of the lens 100 vibrates periodically to control the beam emission density of the sheet-shaped ion beam 20 in the WB direction. For example, each magnetic lens vibration power source 112 is an AC power source, and the vibration current is an AC current, but it is not limited to an AC such that the average value of one cycle is zero.

When such a magnetic lens vibrating power supply 112 is provided, as described above, the beam emission density can be controlled in the magnetic lens 100, thus, the microcosmic (subtle) beam current density distribution in the width WB direction of the ion beam 20 can be adjusted. Therefore, the uniformity of the beam current density distribution in the width WB direction of the sheet-shaped ion beam 20 can be further improved.

The magnetic lens vibration power supply 112 can also be provided together with the magnetic lens magnetic mirror DC power supply 110 . In this case, each magnetic lens DC power supply 110 and each magnetic lens vibration power supply 112 are connected in series to each other, and the vibration voltage from the latter is superimposed on the DC voltage from the former.

As described above, when the two power sources 110 and 112 are used in combination, the following two aspects can be used in combination, that is, the microscopic non-uniformity of the beam current density distribution in the width WB direction of the ion beam 20 is flattened by the magnetic lens vibration power source 112, And use the magnetic lens DC power supply 110 to flatten the larger inhomogeneity, so the uniformity of the beam current density distribution in the width WB direction of the ion beam 20 can be further improved.

Such an electric field lens 24 or magnetic lens 100 may be provided between the ion source 2 and the separation gap 72 . That is, it may be provided on the downstream side of the mass separation magnet 36 instead of on the upstream side of the mass separation magnet 36 . More specifically, it may be provided between the mass separation magnet 36 and the separation gap 72 . In particular, even if an electric field or a magnetic field is applied to the ion beam 20 through the electrostatic lens 24 or the magnetic lens 100 to provide a deflection force to the ion beam 20, a certain distance is required to deflect the ion beam by a predetermined distance. Before the ion beam 20 is incident on the substrate 82 to increase, it is preferable to dispose the electrostatic lens 24 or the magnetic lens 100 on the upstream side of the mass separation magnet 36 .

As described above, since the distance L1 between the magnetic poles of the mass separation magnet 36 is larger than the width WB of the ion beam 20, the magnetic poles are made so as not to enlarge the width of the magnetic poles (the width in the thickness TB direction of the ion beam 20, the same applies below). The parallelism of the magnetic field between them (the parallelism of the thickness TB direction of the ion beam 20, the following is the same) is good, preferably as in this embodiment, the main magnetic pole 38, the first auxiliary magnetic pole 40 and the second auxiliary magnetic pole 42 are set on the mass separation magnet 36 .

That is, referring to FIG. 8 and FIG. 9, the mass separation magnet 36 of this embodiment includes: a pair of main magnetic poles 38, which are arranged oppositely at an interval L1 larger than the width WB of the sheet-shaped ion beam 20, so that the ion beam 20 Through the middle; a pair of first secondary magnetic poles 40, which are arranged on the outer peripheral side of the main magnetic poles 38, are oppositely arranged at an interval L2 (that is, L2<L1) smaller than the interval of the main magnetic poles 38, so that the magnetic field between the main magnetic poles 38 Parallelization: A pair of second auxiliary magnetic poles 42 are provided on the inner peripheral side of the main magnetic poles 38 to make the magnetic field between the main magnetic poles 38 parallel. In FIG. 9 , the main magnetic pole 38 is the cathode of the movable magnetic pole 56 .

The pairs of upper and lower magnetic poles 38 , 40 , 42 are magnetically connected together through a magnetic yoke 44 . In addition, the main magnetic pole 38 , the first sub-magnetic pole 40 , and the second sub-magnetic pole 42 are collectively excited by the exciting coil 46 .

An example of the magnetic field between the main magnetic poles 38 , the magnetic field between the first sub magnetic poles 40 and the magnetic field between the second sub magnetic poles 42 is schematically shown in FIG. 9 by lines of magnetic force 48 , 50 and 52 , respectively. As described above, by satisfying L2<L1 and L3<L1, the magnetic field between the first sub-magnetic poles 40 and the magnetic field between the second sub-magnetic poles 42 sandwiching the magnetic field between the main magnetic poles 38 become larger than the magnetic field between the main magnetic poles 38. Strong, so the magnetic field lines 50 and 52 on both sides can be used to control the reduction of the parallelism of the magnetic field due to the expansion of the magnetic field lines 48 between the main magnetic poles 38, so that the magnetic field lines 48 between the main magnetic poles 38 are parallelized.

As described above, since the magnetic field between the main magnetic poles 38 can be parallelized, when the sheet-like ion beam 20 is bent between the main magnetic poles 38, the generation of Lorentz force in the direction along the sheet-like surface 20s of the ion beam 20 can be suppressed. Bunching or divergence in the width WB direction of the ion beam 20 is suppressed. As a result, the parallelism in the width WB direction of the ion beam 20 can be further improved, and the uniformity of the beam current density distribution in the width WB direction of the ion beam 20 can be further improved. This can be realized without enlarging the width of the main magnetic pole 38 . As a result, the size and weight of the mass separation magnet 36 can be prevented from being enlarged.

The interval L2 of the first auxiliary magnetic pole 40 and the interval L3 of the second auxiliary magnetic pole 42 can also be fixed to the size optimized by computer simulation in advance, but as shown by the arrow H in Figure 9, the first auxiliary magnetic pole 40 and the second auxiliary magnetic pole At least one of the magnetic poles 42 is preferably vertically movable so that the intervals L2 and L3 are variable. In this way, adjustment to further parallelize the magnetic field between the main magnetic poles 38 can be performed. More preferably, both the first sub-magnetic pole 40 and the second sub-magnetic pole 42 are movable, and the distances L2 and L3 between them are variable, so that the adjustment can be performed more accurately and easily. At this time, the moving distances of the paired upper and lower sub-poles 40 and 42 may be the same as or different from each other.

Although the auxiliary magnetic poles 40, 42 with variable intervals can be moved manually, it is preferable to provide an auxiliary magnetic pole drive that moves them up and down as shown by the arrow H and changes the intervals L2 and L3 as in this embodiment. Device 62. In this example, four sub-magnetic pole drive devices 62 for respectively driving the four sub-magnetic poles 40 and 42 are provided. By using the auxiliary magnetic pole drive device 62 , adjustment to further parallelize the magnetic field between the main magnetic poles 38 can be easily performed. Moreover, automatic control may be performed by the control apparatus 94 mentioned later.

On the mass separation magnet 36, with reference to Fig. 8 and Fig. 9, it is also possible to form a semi-cylindrical shape on at least one side of the entrance portion and the exit portion of the main magnetic pole 38, and by the advancing direction of the ion beam 20 (that is, the central axis 20a) The movable pole 56 in which the angle α, β formed by the vertical line 60 and the flat pole surface 58 of the movable pole 56 is variable. In this embodiment, movable magnetic poles 56 are respectively provided at both the entrance portion and the exit portion. The two movable magnetic poles 56 can rotate left and right about the axis 59 as indicated by the arrow G, whereby the angles α and β are variable. As shown in FIG. 8 , the angle α of the entrance and the angle β of the exit are negative (-) when the inner peripheral side of the mass separation magnet 36 enters the inside, and positive (+) when the opposite is true. The angle α or β of the upper and lower movable magnetic poles 56 may be the same as or different from each other.

Since the ion beam 20 passing through the vicinity of the movable magnetic pole 56 can be focused or diverged by adjusting the angles α and β of the movable pole 56, it can compensate (offset) the effect on the sheet ion beam 20. The divergence of the ion beam 20 caused by Coulomb repulsion in the width WB direction further improves the parallelism of the ion beam 20 , and further improves the uniformity of the beam current density distribution in the width WB direction of the ion beam 20 .

The fringe focus effect itself is known, and is described, for example, in "Dictionary of Physics" edited by the Dictionary of Physics Editorial Committee, first edition, Kaifukan Co., Ltd., September 30, 1959, p.182.

The effect of improving the parallelism of the ion beam 20 and the uniformity of beam current density distribution can be realized by arranging a movable magnetic pole 56 on at least one side of the entrance and exit of the main magnetic pole 38, but as described in this embodiment, at the entrance When the movable magnetic pole 56 is arranged on both sides of the part and the outlet part, compared with the case of setting it on one side, the degree of freedom of adjustment can be further improved, and the above-mentioned effect can be improved.

The movable electrode 56 may be provided when the first sub-pole 40 and the second sub-pole 42 are not provided. In this case, the movable electrode 56 may be provided on a magnetic pole corresponding to the main magnetic pole 38 . Others are as above.

The movable magnetic pole 56 can also be rotated by manual operation, but as shown in this embodiment, it is preferable to set the movable magnetic pole drive that rotates the movable magnetic pole 56 left and right as shown by the arrow G to change the angle α, β. Device 66. In this example, four movable magnetic pole drive devices 66 are provided to rotate the four movable magnetic poles 56 at the upper and lower movable magnetic poles 56 at the entrance and the upper and lower movable magnetic poles 56 at the exit of the main magnetic pole 38, respectively. . The adjustment of the angles α, β of the movable magnetic pole 56 can be easily performed by using the movable magnetic pole drive device 66 . In addition, automatic control may be performed by the control apparatus 94 mentioned later.

In addition, due to the vacuum-tight structure of the sub-magnetic poles 40, 42 with variable intervals and the shaft 59 for the movable magnetic pole 56 of the mass separation magnet 36, specifically, the vacuum-tight structure between them and the yoke 44 is in this position. In the example, a well-known structure (for example, a structure using a seal for vacuum sealing) is used, and therefore its illustration is omitted in FIG. 9 .

In the example shown in FIGS. 2 and 4 , a pair of scanning electrodes 74 may be provided on the downstream side of the separation slit 72, and the pair of scanning electrodes 74 are arranged to face each other across the entire sheet surface 20s of the sheet ion beam 20. , scan the entire sheet ion beam 20 reciprocally in a direction perpendicular to the sheet surface 20s. Scanning electrode 74 is a pair of parallel plate electrodes in this example, but it is not limited thereto, and may be an electrode slightly widened toward the downstream side, for example.

An oscillating voltage is applied between the pair of scanning electrodes 74 from the scanning power source 76 . The oscillating voltage is, for example, an AC voltage, but is not limited to an AC voltage in which the average value of one cycle is zero.

The entire ion beam 20 can be scanned in a direction perpendicular to the sheet surface 20 s by the scanning electrode 74 and the scanning power source 76 . As a result, the thickness TB of the ion beam 20 with a very small thickness TB (this can also be the width in the reciprocating drive direction D of the substrate) can be increased by the separation gap 72 . When the thickness TB of the ion beam 20 is very small, the instability of the reciprocating driving speed of the substrate 82 or the current value of the ion beam 20 may cause unevenness in the implantation amount, but this unevenness can be alleviated by increasing the thickness TB of the ion beam 20. Uniformity.

Like the examples shown in FIGS. 2 and 4 , a beam profile monitor 90 may be provided near the downstream side of the substrate 82 on the support frame 84 to receive the sheet ion beam 20 and measure its width WB. The overall beam current density distribution in the direction. The beam profile monitor 90 is preferably positioned adjacent to the substrate 82 on the support frame 84 . In this way, the beam current density distribution of the ion beam 20 at the position of the substrate 82 can be more accurately measured. Measurement information DP indicating the beam current density distribution is output from the beam profile monitor 90 .

As shown in this example, when the beam profile monitor 90 is installed downstream of the substrate 82, since the monitor 90 does not prevent the ion beam 20 from irradiating the substrate 82, it is not necessary to retract the beam profile monitor 90. The beam profile monitor 90 may be initially installed near the upstream side of the substrate 82 and retracted when the ion beam 20 is irradiated on the substrate 82 .

In this example, the beam profile monitor 90 has a plurality of (for example, 29) Faraday cages 92 arranged side by side in a region wider than the width WB of the sheet-shaped ion beam 20 in the direction of the width WB. Therefore, in this example, the measurement information DP is composed of n6 (n6 is the same as the number of 92 Faraday cages) measurement information. The lateral width of each Faraday cage 92 is slightly larger than, for example, the thickness TB of the ion beam 20 incident on the beam profile monitor 90 . However, instead of such a beam profile monitor 90 , a beam profile monitor configured to move one Faraday cage in the width WB direction of the ion beam 20 may be provided. In either case, the beam current density distribution in the width WB direction of the ion beam 20 can be measured.

When the beam profile monitor 90 is provided in advance, since the measurement information DP measured by the monitor 90 can be used, it is possible to easily improve the uniformity of the beam current density distribution in the width WB direction of the sheet-like ion beam 20 or Parallel adjustment.

There are two methods for increasing the beam current density distribution or parallelism in the width WB direction of the ion beam 20 based on the measurement information DP measured by the beam profile monitor 90. The adjustment method of the adjustment is (2) a method of setting the control device 94 (see FIG. 2 ) in advance, taking in the measurement information DP therein, and using the control device 94 to automatically control the target equipment. The target devices are, for example, the filament power supply 8 , the electrostatic lens DC power supply 32 , the magnetic lens DC power supply 110 , the secondary magnetic poles 40 , 42 , and the movable electrode 56 . When the auxiliary magnetic pole drive unit 62 and the movable magnetic pole drive unit 66 are provided, these are also included in the object equipment. When performing automatic control, instead of directly controlling the auxiliary magnetic poles 40, 42 and the movable magnetic pole 56, the control devices 62, 66 used for them are controlled.

The method of adjustment by the operator is briefly as follows. That is, an initial value is provided to each of the target devices in advance, the ion beam 20 is extracted from the ion source 2, the ion beam is received by the beam profile monitor 90, and the incoming current density distribution is measured, and when the result deviates from the target value, the The state of one of the target devices changes from a predetermined value to a predetermined direction, and the beam current density distribution is measured again in this state, and if the measurement result is close to the target value, the adjustment of such changes is continued, for example, away from the target value, Then, it is changed at a predetermined value in the direction opposite to the above, and the adjustment of each such step is repeated until the beam current density distribution measured by the beam profile monitor 90 reaches the target value or approaches the target value to some extent. When the adjustment by one target device is insufficient, it is only necessary to change the target device and perform the same adjustment as described above.

In this embodiment, the control device 94 can perform the controls shown in (a) to (e) below, but not necessarily all of the controls in (a) to (e), and the control device 94 can also perform the controls shown in (a) to (e) below. At least one control. In addition, instead of using one control device 94 , the control of (a) to (e) may be shared by a plurality of control devices. For example, it is also possible to provide a plurality of control devices that respectively perform the control of (a) to (e).

(a) The control device 94 controls the filament power source 8 based on the measurement information DP measured by the beam profile monitor 90, and when there is a low current density region where the beam current density is lower than other regions, the flow corresponding to the low current density region flows The filament current of the filament 6 increases, and in the opposite case (that is, reduces the filament current), the beam current density distribution in the width WB direction of the sheet-shaped ion beam 20 incident on the substrate 82 is uniform. oriented control.

To further show a specific example, since the corresponding relationship between the positions of each Faraday cover 92 of the beam profile monitor 90 and each filament 6 of the ion source 2 is determined in advance, the control device 94 can determine which filament corresponds to the low current density region 6. Moreover, when the low current density region corresponds to, for example, the m-th (m is arbitrary, the same below) filament 6 from the upper part in the Y direction, as described above, the control device 94 increases or decreases the flow into the m-th filament. 6 filament current, repeat this operation until the specified beam current density distribution is obtained.

In order to perform such control, the control device 94 outputs n1 (n1 is the same as the number of filaments 6 ) control signals S1 , and sends the signals to each filament power supply 8 to control each filament power supply 8 respectively.

As mentioned above, by using the beam profile monitor 90 and the control device 94 to feedback and control the filament current of the ion source 2, the beam current density distribution in the width WB direction of the sheet-shaped ion beam 20 incident on the substrate 82 can be improved through automatic control. Uniformity.

(b) The control device 94 controls the electrostatic lens DC power supply 32 based on the measurement information DP measured by the beam profile monitor 90, and when there is a low current density area where the beam current density is lower than other areas, reduce the current applied to the low current. The voltage on the pair of electrodes in the density area, so that the electric field E (refer to FIG. 7 ) is directed from the adjacent area to the area in the said electrostatic lens 24 corresponding to the low density area, and vice versa in the opposite case (i.e. The voltage is increased, the electric field E is decreased or the direction is reversed), and the beam current density distribution in the width WB direction of the sheet-shaped ion beam 20 incident on the substrate 82 is controlled to be uniform.

To further show a specific example, since the position correspondence between each Faraday cage 92 of the beam profile monitor 90 and each electrode pair of the electrostatic lens 24 is determined in advance, the control device 94 can determine which electrode pair corresponds to the low current density region. Furthermore, when the low current density region corresponds to, for example, the m-th electrode pair from the upper part in the Y direction, as described above, the control device 94 increases or decreases the voltage applied to the m-th electrode pair, and this operation is repeated until Obtain the specified beam current density distribution.

It is also possible to increase or decrease the voltage applied to both sides of the m-th electrode pair (that is, the m-1 and m+1) electrode pairs and the voltage applied to the m-th electrode pair in a predetermined relationship. .

In order to perform such control, the control device 94 outputs n2 (n2 is the same as the number of electrode pairs) control signals S2, which are respectively given to the DC power supplies 82 of the electrostatic lenses to control the DC power supplies 32 of the electrostatic lenses respectively.

As mentioned above, the electrostatic lens 24 can be feedback-controlled by the beam profile monitor 90 and the control device 94, and the uniformity of the beam current density distribution in the width WB direction of the sheet-shaped ion beam 20 incident on the substrate 82 can be improved through automatic control.

(c) The control device 94 controls the magnetic lens DC power supply 110 based on the measurement information DP measured by the beam profile monitor 90, and when there is a low current density area where the beam current density is lower than other areas, adjusts the flow rate corresponding to the low current density. The current of the excitation coil 104 of the magnetic pole pair near the region of the region is to increase the Lorentz force F of the region in the magnetic lens 100 corresponding to the low density region from its adjacent region (refer to FIG. 11 ), and in the opposite case, do the opposite (that is, reduce the Lorentz force F or reverse the orientation), so that the beam current density distribution in the width WB direction of the sheet-shaped ion beam 20 incident on the substrate 82 is made uniform.

To further show a specific example, since the position correspondence between each Faraday cage 92 of the beam profile monitor 90 and each magnetic pole pair of the magnetic lens 100 is determined in advance, the control device 94 can determine which magnetic pole pair the low current density region corresponds to. Moreover, when the low current density region corresponds to, for example, the mth magnetic pole pair from the upper part in the Y direction, as described above, the control device 94 increases the current flowing into the exciting coil 104 of the m−1th magnetic pole pair (FIG. 11 In the direction of the magnetic field B shown), the Lorentz force F is increased towards the low current density region. At this time, the polarity of the m+1 magnetic lens DC power supply 110 can also be reversed at the same time, so that the direction of the magnetic field B generated by the m+1 magnetic pole pair is reversed, increasing the magnetic field from the m+1 magnetic pole pair Lorentz force F towards the low current density region. The same applies to the case where the low current density region is located between the magnetic pole pairs.

The current flowing into the two sides of the m-1 and m+1 magnetic pole pairs (that is, the m-2 and m+2) magnetic pole pairs can also flow into the m-1 and m+1 according to the sum The relation of the current regulation of the magnetic pole pair is controlled as described above.

In order to carry out such control, the control device 94 outputs n3 (n3 is the same as the number of magnetic pole pairs) control signals S3, which are respectively given to each pole lens DC power supply 110 to control each pole lens DC power supply 110 respectively.

As mentioned above, the magnetic lens 110 can be feedback-controlled by the beam profile monitor 90 and the control device 94, and the uniformity of the beam current density distribution in the width WB direction of the sheet-shaped ion beam 20 incident on the substrate 82 can be improved through automatic control.

(d) The control unit 94 controls the sub-magnetic pole drive unit 62 based on the measurement information DP measured by the beam profile monitor 90, and when the beam current density distribution diverges from a predetermined target value, the sub-pole driving unit 62 is driven to and from the mass separation magnet 36. The derived ion beam 20 changes the intervals L2, L3 of the secondary magnetic poles 40, 42 whose intervals L2, L3 are variable in the direction parallel to the in-plane converging of its sheet surface 20s, and vice versa in the opposite case (i.e. The interval L2, L3) is changed in the direction in which the ion beam 20 diverges, and the parallelism of the width WB direction of the sheet-like ion beam 20 incident on the substrate 82 is controlled to be improved.

In a more specific example, when the divergence of the beam current density distribution exceeds the target value, the control device 94 increases the interval L2 of the first sub-magnetic poles 40 on the outer peripheral side and narrows the interval L3 of the second sub-magnetic poles 42 on the inner peripheral side. When the beamforming exceeds the target value, it is opposite to the above.

In order to carry out such control as described above, the control device 94 outputs n4 (n4 is the same as the number of auxiliary magnetic pole driving devices 62) control signals S4, and this signal is given to each auxiliary magnetic pole driving device 62 respectively to control each auxiliary magnetic pole driving device 62 respectively. .

As described above, the intervals L2 and L3 between the secondary magnetic poles 40 and 42 of the mass separation magnet 36 can be feedback-controlled by the beam profile monitor 90 and the control device 94, and the width of the sheet-shaped ion beam 20 incident on the substrate 82 can be increased by automatic control. The parallelism of the WB direction improves the uniformity of the beam current density distribution.

(e) The control unit 94 controls the movable magnetic pole drive unit 66 based on the measurement information DP measured by the beam profile monitor 90, and when the distribution of the beam current density diverges from a predetermined target value, it moves to the mass separation magnet. The ion beam 20 derived from 36 rotates the movable magnetic pole 56 in the direction parallel to the in-plane converging direction of the sheet surface 20s, and in the opposite case (rotates in the direction in which the ion beam 20 diverges), Control is performed to increase the parallelism in the width WB direction of the sheet-shaped ion beam 20 incident on the substrate 82 .

To further show a specific example, when the divergence of the beam current density distribution exceeds the target value, the control device 94 makes the angles α, β more toward the positive direction, and when the beam focusing exceeds the target value, makes the angles α, β more toward the negative direction. direction change.

In order to carry out such control as described above, the control device 94 outputs n5 (n5 is the same as the number of the movable magnetic pole driving device 66) control signals S5, and the signal is given to each movable magnetic pole driving device 66 respectively to control each movable magnetic pole driving device 66 respectively. Drive 66.

As described above, the angles α, β of the movable magnetic pole 56 of the mass separation magnet 36 can be feedback-controlled by the beam profile monitor 90 and the control device 94, and the width WB of the sheet-shaped ion beam 20 incident on the substrate 82 can be increased by automatic control. The parallelism of the direction improves the uniformity of the beam current density distribution.

Claims (18)

1, a kind of ion implantation apparatus, the wide sheet ion beam of the minor face width of the ratio substrate that will produce by ion source with the state that keeps this width relation to substrate transfer, shine on the substrate, it is characterized in that, comprise: ion source, its generation has the ionic species of desired injection substrate and has the sheet ion beam of described width relation, and described ion source is used to generate the plasma in the source that forms this sheet ion beam and has a plurality of filaments of arranging in this sheet ion beam width direction; More than one A-power supply, it can separate control flows into the heater current of this ionogenic each filament; Mass separation magnet, it receives the sheet ion beam that is produced by described ion source, has the magnetic pole at the interval bigger than the width of this ion beam, with this ion beam to the direction bending of its sheet face quadrature, described desirable ionic species is derived in screening; Separate the slit, it receives from sheet ion beam and this mass separation magnet association that this mass separation magnet is derived moving, screens described desirable ionic species and it is passed through; The substrate drive unit, it has the bearing support that keeps substrate, back and forth drives substrate on the bearing support along the direction with the sheet hand-deliver fork of this ion beam in the irradiation area of the sheet ion beam by described separation slit; Electrostatic lens or magnetic lens are between described ion source and described mass separation magnet or in described mass separation magnet and described being evenly distributed of beam current density of separating the Width that makes described sheet ion beam between the slit.

2, ion implantation apparatus as claimed in claim 1 is characterized in that, described electrostatic lens also comprises at least one electrostatic lens DC power supply, and it applies separate direct voltage respectively between each electrode pair of this electric field lens and reference potential portion,

Described electrostatic lens has a plurality of electrode pairs, this electrode pair clips the sheet of described sheet ion beam and faces to configuration, be arranged side by side along right angle orientation along this sheet face and with respect to the direction of advance of bundle, will be positioned at the sheet ion beam arbitrary region ion along the sheet face of this ion beam and to the direction bending of the direction of advance quadrature of bundle.

3, ion implantation apparatus as claimed in claim 2, it is characterized in that, also comprise: electrostatic lens vibration power supply, it replaces described electrostatic lens DC power supply, or and described electrostatic lens DC power supply between the strange sequence number of described electrostatic lens and even sequence number electrode pair, apply vibration voltage together, make the electric field strength periodic vibration of described electrostatic lens, control is along the sheet face of described sheet ion beam and perpendicular to the bundle emission density of the direction of bundle direction of advance.

4, ion implantation apparatus as claimed in claim 1 is characterized in that, described magnetic lens also comprises a plurality of magnetic lens DC power supply, and its each magnet exciting coil to this magnetic lens flows into direct current respectively,

Described magnetic lens has a plurality of pole pairs and a plurality of magnet exciting coil, these a plurality of pole pairs clip the sheet of described sheet ion beam and face to configuration, be arranged side by side along right angle orientation along this sheet face and with respect to the direction of advance of restrainting, described magnet exciting coil makes each pole pair excitation respectively, and described magnetic lens will be positioned at the ion of arbitrary region of sheet ion beam along the sheet face of this ion beam and to the direction bending with respect to the direction of advance quadrature of bundle.

5, ion implantation apparatus as claimed in claim 4, it is characterized in that, also have a plurality of magnetic lens vibration power supplys, it replaces described magnetic lens DC power supply, or and described magnetic lens DC power supply flow into oscillating current respectively to each magnet exciting coil of described magnetic lens together, make the magnetic field intensity periodic vibration of described magnetic lens, control is along the sheet face of described sheet ion beam and perpendicular to the bundle emission density of the direction of bundle direction of advance.

6, ion implantation apparatus as claimed in claim 1 is characterized in that, described mass separation magnet comprises: a pair of main pole, and it is provided with the interval subtend bigger than the width of described sheet ion beam, and the ion beam that makes described sheet is by therebetween; A pair of first secondary magnetic pole, it is located at the outer circumferential side of this main pole, is provided with the interval subtend littler than main pole, with the magnetic field parallelization between main pole; A pair of second secondary magnetic pole, it is located at interior all sides of described main pole, is provided with the interval subtend littler than main pole, with the magnetic field parallelization between main pole; Magnet exciting coil, it makes described main pole, first secondary magnetic pole and the second secondary magnetic pole excitation.

7, ion implantation apparatus as claimed in claim 6 is characterized in that, at least one variable spaced in described first secondary magnetic pole and second secondary magnetic pole.

8, ion implantation apparatus as claimed in claim 7 is characterized in that, moves the secondary magnetic pole drive unit that changes its interval thereby have the secondary magnetic pole that makes described variable spaced.

9, ion implantation apparatus as claimed in claim 1, it is characterized in that described mass separation magnet has the movable magnetic pole of the variable-angle that forms semi-cylindrical and be made of thickness direction and magnetic pole end face with the sheet ion beam at least one of the inlet of described magnetic pole and outlet.

10, ion implantation apparatus as claimed in claim 6, it is characterized in that described mass separation magnet has the movable magnetic pole of the variable-angle that forms semi-cylindrical and be made of thickness direction and magnetic pole end face with the sheet ion beam at least one of the inlet of described magnetic pole and outlet.

11, ion implantation apparatus as claimed in claim 9 is characterized in that, makes described movable magnetic pole rotation change the movable magnetic pole drive unit of described angle thereby have.

12, ion implantation apparatus as claimed in claim 1, it is characterized in that, also comprise: a pair of scan electrode, it is positioned at the downstream in described separation slit, the whole sheet that clips described sheet ion beam is in the face of to configuration, with the described sheet ion beam of the direction shuttle-scanning integral body of sheet face quadrature; Scanning power supply, it applies vibration voltage between this a pair of scan electrode.

13, ion implantation apparatus as claimed in claim 1 is characterized in that, also has bundle profile monitor, and upstream side or downstream that it is located at the substrate on the described bearing support receive described sheet ion beam, and the beam current density of measuring its Width distributes.

14, ion implantation apparatus as claimed in claim 1 is characterized in that, also comprises: bundle profile monitor, and upstream side or downstream that it is located at the substrate on the described bearing support receive described sheet ion beam, and the beam current density of measuring its Width distributes; Control device, the described A-power supply of mensuration information Control that it is measured based on this bundle profile monitor, when having beam current density than other regional low low current density areas, inflow is increased the heater current of described filament that should low current density areas, otherwise under opposite situation, carry out and to incide the control of being evenly distributed of beam current density of the Width of the sheet ion beam on the substrate.

15, ion implantation apparatus as claimed in claim 2 is characterized in that, also comprises: bundle profile monitor, and upstream side or downstream that it is located at the substrate on the described bearing support receive described sheet ion beam, and the beam current density of measuring its Width distributes; Control device, the described electrostatic lens DC power supply of mensuration information Control that it is measured based on this bundle profile monitor, when having beam current density than other regional low low current density areas, voltage on the described electrode pair that is applied to corresponding described low current density areas is reduced, so that electric field from adjacent areas towards to the zone should the described electrostatic lens of density regions, otherwise under opposite situation, carry out and to incide the control of being evenly distributed of beam current density of the Width of the sheet ion beam on the substrate.

16, ion implantation apparatus as claimed in claim 4 is characterized in that, comprising: bundle profile monitor, and upstream side or downstream that it is located at the substrate on the described bearing support receive described sheet ion beam, and the beam current density of measuring its Width distributes; Control device, the described magnetic lens DC power supply of mensuration information Control that it is measured based on this bundle profile monitor, when having beam current density than other regional low low current density areas, adjust near the electric current of the magnet exciting coil of the regional described pole pair that flows into corresponding described low current density areas, to increase from adjacent area towards Lorentz force to the zone should the described magnetic lens of density regions, otherwise under opposite situation, carry out and to incide the control of being evenly distributed of beam current density of the Width of the sheet ion beam on the substrate.

17, ion implantation apparatus as claimed in claim 8 is characterized in that, comprising: bundle profile monitor, and upstream side or downstream that it is located at the substrate on the described bearing support receive described sheet ion beam, and the beam current density of measuring its Width distributes; Control device, the described secondary magnetic pole drive unit of mensuration information Control that it is measured based on this bundle profile monitor, compare with the desired value of regulation when dispersing at beam current density, to making the interval that changes the secondary magnetic pole of described variable spaced from the ion beam of described mass separation magnet derivation in the direction of the face internal bunching that is parallel to its sheet face, otherwise under opposite situation, improve the control of collimation of the Width of the sheet ion beam that incides on the substrate.

18, ion implantation apparatus as claimed in claim 11 is characterized in that, also comprises: bundle profile monitor, and upstream side or downstream that it is located at the substrate on the described bearing support receive described sheet ion beam, and the beam current density of measuring its Width distributes; Control device, the described movable magnetic pole drive unit of mensuration information Control that it is measured based on this bundle profile monitor, compare with the desired value of regulation when dispersing at beam current density, to making the ion beam of deriving make described movable magnetic pole rotation in the direction of the face internal bunching that is parallel to its sheet face from described mass separation magnet, otherwise under opposite situation, improve the control of collimation of the Width of the sheet ion beam that incides on the substrate.

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